OBJECTIVES: Simplified methods for virological monitoring in resource-limited settings are increasingly needed. We evaluated the performance of the VERSANT(®) HIV-1 RNA (kPCR) assay for the determination of HIV-1 viral load from dried blood spots (DBS). Assay sensitivity and correlation with plasma quantification values were assessed. METHODS: A total of 98 DBS were prepared from fresh blood samples of HIV-infected patients. DBS were kept at room temperature for 6 weeks or 7 months before processing while the corresponding plasma samples were stored at -80°C. DBS were first pre-treated in a special DBS buffer. The DBS extracts and the plasma samples were then purified and amplified using the VERSANT assay reagents. RESULTS: In the first series of tests, performed after 6 weeks of storage, there was good correlation between quantification of viral load in plasma and in DBS (r = 0.95, P < 0.001). The detection rate in DBS was 100% when plasma levels were >1000 copies/mL. The sensitivity and specificity of the DBS assay were 88.2% [95% confidence interval (CI) 79.4-93.6] and 69.2% (95% CI 42.0-87.4), respectively. Using the 5000 copies/mL threshold (defining virological failure in resource-limited settings), both positive and negative predictive values were high (95.2% and 87.5%, respectively). After 7 months of storage there was a modest decrease in the detection rate and less significant correlations for samples with HIV-RNA <5000 copies/mL. CONCLUSIONS: Quantification of HIV-RNA from DBS by the VERSANT automated sample preparation and detection method can be used to diagnose virological failure in HIV-positive patients.
OBJECTIVES: Simplified methods for virological monitoring in resource-limited settings are increasingly needed. We evaluated the performance of the VERSANT(®) HIV-1 RNA (kPCR) assay for the determination of HIV-1 viral load from dried blood spots (DBS). Assay sensitivity and correlation with plasma quantification values were assessed. METHODS: A total of 98 DBS were prepared from fresh blood samples of HIV-infectedpatients. DBS were kept at room temperature for 6 weeks or 7 months before processing while the corresponding plasma samples were stored at -80°C. DBS were first pre-treated in a special DBS buffer. The DBS extracts and the plasma samples were then purified and amplified using the VERSANT assay reagents. RESULTS: In the first series of tests, performed after 6 weeks of storage, there was good correlation between quantification of viral load in plasma and in DBS (r = 0.95, P < 0.001). The detection rate in DBS was 100% when plasma levels were >1000 copies/mL. The sensitivity and specificity of the DBS assay were 88.2% [95% confidence interval (CI) 79.4-93.6] and 69.2% (95% CI 42.0-87.4), respectively. Using the 5000 copies/mL threshold (defining virological failure in resource-limited settings), both positive and negative predictive values were high (95.2% and 87.5%, respectively). After 7 months of storage there was a modest decrease in the detection rate and less significant correlations for samples with HIV-RNA <5000 copies/mL. CONCLUSIONS: Quantification of HIV-RNA from DBS by the VERSANT automated sample preparation and detection method can be used to diagnose virological failure in HIV-positivepatients.
Authors: Andrew Phillips; Amir Shroufi; Lara Vojnov; Jennifer Cohn; Teri Roberts; Tom Ellman; Kimberly Bonner; Christine Rousseau; Geoff Garnett; Valentina Cambiano; Fumiyo Nakagawa; Deborah Ford; Loveleen Bansi-Matharu; Alec Miners; Jens D Lundgren; Jeffrey W Eaton; Rosalind Parkes-Ratanshi; Zachary Katz; David Maman; Nathan Ford; Marco Vitoria; Meg Doherty; David Dowdy; Brooke Nichols; Maurine Murtagh; Meghan Wareham; Kara M Palamountain; Christine Chakanyuka Musanhu; Wendy Stevens; David Katzenstein; Andrea Ciaranello; Ruanne Barnabas; R Scott Braithwaite; Eran Bendavid; Kusum J Nathoo; David van de Vijver; David P Wilson; Charles Holmes; Anna Bershteyn; Simon Walker; Elliot Raizes; Ilesh Jani; Lisa J Nelson; Rosanna Peeling; Fern Terris-Prestholt; Joseph Murungu; Tsitsi Mutasa-Apollo; Timothy B Hallett; Paul Revill Journal: Nature Date: 2015-12-03 Impact factor: 49.962
Authors: Pieter W Smit; Kimberly A Sollis; Susan Fiscus; Nathan Ford; Marco Vitoria; Shaffiq Essajee; David Barnett; Ben Cheng; Suzanne M Crowe; Thomas Denny; Alan Landay; Wendy Stevens; Vincent Habiyambere; Joseph H Perriens; Rosanna W Peeling Journal: PLoS One Date: 2014-03-06 Impact factor: 3.240
Authors: Lara Vojnov; Sergio Carmona; Clement Zeh; Jessica Markby; Debrah Boeras; Marta R Prescott; Anthony L H Mayne; Souleymane Sawadogo; Christiane Adje-Toure; Guoqing Zhang; Mercedes Perez Gonzalez; Wendy S Stevens; Meg Doherty; Chunfu Yang; Heather Alexander; Trevor F Peter; John Nkengasong Journal: PLoS Med Date: 2022-08-22 Impact factor: 11.613